To improve the smoothness of the knitting operation during a knitting process of a circular knitting machine, the cotton yarn must be tightly pulled, and the cotton yarns usually produce cotton fibers in the process of inputting, guiding, and feeding the cotton yarns. If these cotton fibers are not removed, each component of the circular knitting machine will get stuck easily, and that will affect the smoothness of the knitting operation and shorten the life of the circular knitting machine. Furthermore, defects will be produced if the cotton fibers and the cotton yarns are knitted together to produce a piece of cloth, and that will affect the quality of the cloth.
In view of the foregoing problems, many prior art mechanisms for clearing cotton fibers have been proposed, such as R.O.C. Patent Publication No. 286689 entitled “Dust disposal device of circular knitting machine”, R.O.C. Patent Publication No. 267459 entitled “Fiber blowing device of circular knitting machine”, and R.O.C. Patent Publication No. 429974 entitled “Improved fiber blowing device of circular knitting machine” etc, wherein “Dust disposal device of circular knitting machine” mainly discloses a dust disposal device driven by a crank rod mechanism to sway a fiber blowing fan up and down, and “Fiber blowing device of circular knitting machine” mainly discloses a device having a rotary nozzle, and the rotary nozzle has several nozzles capable of emitting air towards different tangential directions. When the air is emitted, the nozzle rotates automatically to produce a centralized airflow on the vertical lead surface of the circular knitting machine, and “Improved thread end removing vibratory pipe of knitting machine” mainly discloses a design of using pressurized air to go through a soft flexible tube and a thickness of the wall of the soft tube to improve the accuracy of guiding air to the target area.
It is worth to point out that most of the fiber blowing devices for the circular knitting machine blow at the yarn feeding position. However, the inventor of the present invention discovered that cotton fibers are produced easily at the positions of the yarn passing plate, yarn feeding nozzle, and knitting needle of the circular knitting machine, since the yarn passing plate and the yarn feeding nozzle have holes and openings for passing the cotton yarns in the knitting process. The cotton yarn will keep on rubbing the holes and openings of the yarn passing plate and the yarn feeding nozzle to produce cotton fibers, and the knitting needle produces cotton fibers easily during the processes of rotating and hooking the yarns. With long-time high-speed rotations, the knitting needle generally produces a high temperature. For present traditional fiber blowing devices, no measures for centralizing the airflow to blow fibers at the positions of easily producing cotton fibers and lower the temperature at the positions of producing heat are taken into consideration for the circular knitting machine. Thus, finding a way of effectively blowing away the cotton fibers and lowering the temperature for the applications of the present circular knitting machine demands immediate attentions and feasible solutions.